mathjs/lib/function/matrix/ones.js

'use strict';

var isInteger = require('../../utils/number').isInteger;
var resize = require('../../utils/array').resize;

function factory (type, config, load, typed) {
  var matrix = load(require('../../type/matrix/function/matrix'));

  /**
   * Create a matrix filled with ones. The created matrix can have one or
   * multiple dimensions.
   *
   * Syntax:
   *
   *    math.ones(m)
   *    math.ones(m, format)
   *    math.ones(m, n)
   *    math.ones(m, n, format)
   *    math.ones([m, n])
   *    math.ones([m, n], format)
   *    math.ones([m, n, p, ...])
   *    math.ones([m, n, p, ...], format)
   *
   * Examples:
   *
   *    math.ones(3);                   // returns [1, 1, 1]
   *    math.ones(3, 2);                // returns [[1, 1], [1, 1], [1, 1]]
   *    math.ones(3, 2, 'dense');       // returns Dense Matrix [[1, 1], [1, 1], [1, 1]]
   *
   *    var A = [[1, 2, 3], [4, 5, 6]];
   *    math.ones(math.size(A));       // returns [[1, 1, 1], [1, 1, 1]]
   *
   * See also:
   *
   *    zeros, eye, size, range
   *
   * @param {...number | Array} size    The size of each dimension of the matrix
   * @param {string} [format]           The Matrix storage format
   *
   * @return {Array | Matrix | number}  A matrix filled with ones
   */
  var ones = typed('ones', {
    '': function () {
      return (config.matrix === 'Array')
          ? _ones([])
          : _ones([], 'default');
    },

    // math.ones(m, n, p, ..., format)
    // TODO: more accurate signature '...number | BigNumber, string' as soon as typed-function supports this
    '...number | BigNumber | string': function (size) {
      var last = size[size.length - 1];
      if (typeof last === 'string') {
        var format = size.pop();
        return _ones(size, format);
      }
      else if (config.matrix === 'Array') {
        return _ones(size);
      }
      else {
        return _ones(size, 'default');
      }
    },

    'Array': _ones,

    'Matrix': function (size) {
      var format = size.storage();
      return _ones(size.valueOf(), format);
    },

    'Array | Matrix, string': function (size, format) {
      return _ones (size.valueOf(), format);
    }
  });

  ones.toTex = undefined; // use default template

  return ones;

  /**
   * Create an Array or Matrix with ones
   * @param {Array} size
   * @param {string} [format='default']
   * @return {Array | Matrix}
   * @private
   */
  function _ones(size, format) {
    var hasBigNumbers = _normalize(size);
    var defaultValue = hasBigNumbers ? new type.BigNumber(1) : 1;
    _validate(size);

    if (format) {
      // return a matrix
      var m = matrix(format);
      if (size.length > 0) {
        return m.resize(size, defaultValue);
      }
      return m;
    }
    else {
      // return an Array
      var arr = [];
      if (size.length > 0) {
        return resize(arr, size, defaultValue);
      }
      return arr;
    }
  }

  // replace BigNumbers with numbers, returns true if size contained BigNumbers
  function _normalize(size) {
    var hasBigNumbers = false;
    size.forEach(function (value, index, arr) {
      if (value && value.isBigNumber === true) {
        hasBigNumbers = true;
        arr[index] = value.toNumber();
      }
    });
    return hasBigNumbers;
  }

  // validate arguments
  function _validate (size) {
    size.forEach(function (value) {
      if (typeof value !== 'number' || !isInteger(value) || value < 0) {
        throw new Error('Parameters in function ones must be positive integers');
      }
    });
  }
}

exports.name = 'ones';
exports.factory = factory;